#include <bits/stdc++.h>
using namespace std;
int main()
{
  int n, l, r;
  cin >> n >> l >> r;

  string
      s;
  cin >> s;
  s = " " + s;

  for (int i = l; i <= r; i++)
  {
    if (s[i] == 'x')
    {
      cout << "No" << endl;
      return 0;
    }
  }
  cout << "Yes" << endl;
  return 0;
}